AOL acquired The Huffington Post in February; Armstrong made his contribution to the campaign on June 8.

UPDATE: Huffington Post political editor Sam Stein emails:

As CEO, Tim Armstrong plays no editorial role at The Huffington Post. It’s Arianna, as Editor-in-Chief, who oversees the newsroom, and she does not make any political contributions.

A NOTE TO READERS: Many media executives make campaign contributions that they are not expected to disclose when their network or newspaper interviews a candidate. (I.e., the Huffington Post didn't do anything out of the ordinary here.) But those contributions and their potential consequences are of great interest here at the intersection of media and politics, and will continue to be reported on. So if you've noticed any media-related campaign contributions you think warrant mention, please send them over.